An ultrasonic diagnostic apparatus is designed to apply ultrasonic pulses generated from vibration elements provided on an ultrasonic probe into an object and acquire biological information by receiving reflected ultrasonic waves caused by acoustic impedance differences in the tissue of the object through the vibration elements. This apparatus can display image data in real time by simple operation of bringing the ultrasonic probe into contact with the body surface. The apparatus allows to observe a moving object such as a heart and is therefore widely used for morphological diagnosis and functional diagnosis of the circulatory region and various kinds of organs. To improve the viewability of an ultrasonic image acquired by such an ultrasonic diagnostic apparatus, it is necessary to appropriately set and adjust the intensity (tone) of brightness and the like in accordance with the object.